State officials are scrambling to find out why a hog disease known as
pseudorabies spread rapidly this winter in southern Minnesota's prime pork-raising areas. Over 200 infected herds are quarantined and officials
expect to find more animals with the virus.

QUARANTINED HOGS ARE NOT
a total loss; producers can still sell them for
slaughter. The virus does not affect humans so the meat is safe to eat. But the
disease can kill hogs, and for those that survive it adds thousands of dollars
to the cost of getting them to market. Southern Minnesota producer Kurt Unke
has seen the bills pile up.

Unke:
Just all the blood testing itself and the time to get it done.
And of course the vaccine expense. And your pigs do not grow as good when you
have pseudo.

Those slower growth rates require more feed to get the animals to market
weight. The extra cost is an added blow to hog farmers already facing
depressed market prices. The disease also limits some of the available markets
for Minnesota pork producers. Unke says South Dakota officials refuse entry to
pseudorabies infected hogs because they're concerned the virulent Minnesota
strain will spread to their herds:

Unke:
Even though we raise as good a hogs as anywhere in the country, you have another state say "well we don't want Minnesota hogs because of the
pseudo. " That's bad.

The disease strikes hardest at young pigs, killing many at birth. Pseudorabies
less-frequently kills adult hogs, but it has done that this winter in southern
Minnesota. The virus is spread readily through saliva and mucus, but it can
also travel through the air. Once infected, a hog carries the virus the rest of
its life and may pass it on to other animals, including cats and dogs.

The
disease got its name from the rabies-like symptoms it produces in dogs, such as
foaming at the mouth. State veterinarian Tom Hagerty says the number of
infected hog herds in Minnesota had been declining steadily this decade. In
fact, officials had hoped to eradicate the disease by next year, something which
seems unlikely now. Hagerty has theories, but doesn't know what caused the
winter flare-up.

Hagerty:
Whether it was the fact that we have had and experienced a
great deal of swine influenza which we know will trigger the pseudorabies. Or
if just the fact that producers were unable or unwilling to maintain their
vaccination schedule.

Hagerty speculates low hog prices forced producers to cut costs, with
pseudorabies vaccinations among the items discarded. Hagerty says since last
fall, records show the amount of vaccine sold is not enough for the number of
hogs in the state. Producer Kurt Unke says some farmers wonder about
other reasons for the outbreak.

Unke:
We have done a lot of expansion in this area in the last five to seven
years.

Some believe the growth of the hog industry contributed to the pseudorabies
outbreak. Unke farms in Martin County's Rutland township, one of the most hog-intensive townships in the state's top pork-producing county. New hog farms dot
the landscape. Pseudorabies is rampant and farmers speculate the hog buildings
are just the right distance apart to provide a stepping-stone-like path for the
virus to travel. State veterinarian Hagerty says the problem with the stepping-
stone theory is that no one knows if the virus can ride the wind from farm to
farm, because it's not certain just how far it can travel.

Hagerty:
People talk about quarter mile, one mile, maybe a mile and a
half. But I don't think that there's ever been a good enough study done to say
that the virus will go X number of miles under certain environmental
conditions.

Another theory is that the virus was carried from farm to farm by vehicles.
Hog producer Kurt Unke suspects the semis used to transport hogs to market.

Unke:
In the wintertime it's very hard for the trucker to keep the truck
spotless, washed, disinfected, cleaned-out in between different farms. I guess
my concern is that there's always a possibility of transferring, whether it's
pseudo or any other bug the industry can get here, without having the trucks
cleaned, washed, disinfected in between groups.

State veterinarian Hagerty says state law requires that trucks be disinfected
after hauling quarantined hogs. But he says whether truckers follow that
requirement is mostly on the honor system.

Hagerty:
I know we do not have the personnel to do any sort of
enforcement of that. I would say there has been very little enforcement of that
requirement.

It's also possible that the southern Minnesota outbreak is a new, more virulent
strain of pseudorabies. The virus has mutated in the past, most recently in the
1960s. Researchers say chances that something similar has occurred this winter
are remote, but they are isolating and studying the virus to make sure.

Mark Steil covers southwest Minnesota for Minnesota Public Radio. You can reach him at msteil@mpr.org.